Manufacture of heat exchange apparatus



P 1, 1936- J. D. FORRER ET AL 2,053,239

MANUFACTURE OF HEAT EXCHANGE APPARATUS Filed Oct. 5, 1954 Lewjs E. Prouyh v Patented Sept. 1, 1936 2,053,239

UNITED STATES PATENT OFFICE MANUFACTURE OF HEAT EXCHANGE APPARATUS Joseph I). Forrcr and Lewis B. Prough, Jackson,

Mich, assignors to Acme Industries, Inc., Jackson, Mich. a corporation of Michigan Application October 5, 1934, Serial No. 746,953

4 Claims. (Cl. 29-1573) The present invention relates to the manufaction of the fin structure defining the aperture ture of heat exchange apparatus for heating or takes the form of an axially extending flange cooling a medium surrounding, located within, or and the contraction of such a flange upon the flowing through the apparatus, as for example, body of the heat exchange apparatus without 5 a radiator for the heating of buildings, and the relative axial displacement after such contrac- 5 like, or a refrigerating or cooling unit for the tion, provides adequate contact between the lowering of temperature in rooms, cabinets and parts for eflicient heat transfer. In the drawthe like. ing, for the purpose of illustration, two satis- More specifically the present invention profactory ways of carrying out the invention are vides a method of attachment of a fin or flange shown. innumerable other ways of reforming 10 or equivalent structure upon a tubing or conduit or working t e area 01 e t o flange Strucor equivalent structure of a heat exchange ap ture contiguous with or defining the aperture paratus for increasing the efilciency of the apto effect an inward displacement or contracparatus. In addition, the present invention retion of the aperture or portion thereof upon the lates to an improved heat exchange apparatus body f t at x a pp ra us will r adily 15 in which flanges or fins or equivalent structures suggest themselves and are all considered within are contracted upon the body of the apparatus the range 01 h pr t i v ti n as fined and are of such configuration as to provide efby the appended claims.

ficient heat transfer, adequate rigidity, and per- Having specific reference to the illustrated g0 manency of attachment. forms of the invention,

Heretofore at least one method has been pro- 1 is a Side elevation of Section Of a heat vided for the attachment of fins or fianges by exchange pp contraction upon tubular bodies by first ex- 7 Flgs- 2 and 3 are enlarged a en al ross pend n the fin within its elastic limit by the sectional views of the reforming operation of insertion of the tubular body into a flanged apt Of the fin Structure defining its aperture 25 erture of the fin, as is disclosed in U. s. Patent t contract t s u t t and No. 1,787,942. Such a method necessitates rela- Figs- 4 a 5 e Views Similar t F 2 a d 3 tive movement between the fin and tubular body of a modified form of the inventionduring assembly with the fin contracted upon As illustrated, the body of the heat exchange 3 the body and necessarily impairs the original m take the form of a tube of su b e maso effectiveness of the union. This method gente a which does not necessarily e to po e s erally requires the further operation of expan mandrel expandable characteristics as has been ing the tube with a mandrel in order to obtain heretofore necessary in methods requiring e sufficient binding between the fin and body with expanding 0f the tube to Prevent t fi s om the fin in its final assembled position. Mores t p t some and t p d ad quate 35 over, this method does not readily lend itself to contact between the fins and the tubein spacing and afiixing the fin upon tub l bodies sheet metal fins or flanges H of suitable configand the like by automatic machinery. uration are shown spaced along the tube l0 According to the present invention, the fin, and amxed in Position avoiding Shifting during flange, or equivalent structure employed to ma- Ordinary use in a manner to e na ter eX- 40 terially increase the surface exposed to the P treated medium, is preferably loosely received Referring t 2, the fin I2 is Shown loosely upon the body of the heat exchange apparatus embracing the tube It passed t ou h an aperand t through t employment of t b ture ll defined therein by an integral flange fomning means is contracted or shrunk upon the i6. Preferably at the time the fin I2 is punched 45 body to frictionally engage the same with a to provide the aperture I4 and drawn to provide stressed contact giving high efliciency of heat the flange l6, h 18 formed i t y c nic l transmission between the parts. This method to facilitate the radially rolling of the outer edge of fin assembly lends itself exceedingly well to It as shown in Fig. 3. Suitable forming tools 60 t m ti handling, spacing and aflixing the fins 2c, 22 are diagrammatically shown for reforming upon the tubing as the fins are loosely received he flan w the fin P p y P s ion d thereon until the forming operation. This perupon the tube in, to shrink or contract the apermits the fins to be readily manipulated axially ture l4 defined by the flange. In practice the relative to the tubing to effect proper spacing. tools 20, 22 are made up of two sections which are In the preferred form of the invention, that por-i moved in toward the tube from opposite direc- 55 tions to encircle the same. The tool 22 may be fixed against movement axially of the tube and its thickness determines the minimum spacing of the fins l2 upon the tube I 0. With the fin i2 preferably loosely positioned upon the tube III, the fin l2 may be urged toward the fixed tool 22 by the tool 20. As the edge ll of the flange I. engages the tool 22 the same is rolled to form a radial outwardly turned annular flange 24. With the flange l6 confined and supported circumferentially and axially of the tube In by the tool 20 and 22, the rolling of the edge I8 causes a flowing of the metal located between the tools 20, 22 radially inward in all directions to shrink or reduce the diameter of the aperture It. This action is carried out until the fin l2 has been shrimk or contracted upon the tube sufllciently to prevent shifting of the fin under ordinary use and a pressure or stressed contract has been provided between the fin and tube. As is shown in Fig. 3 the area contact between the fin l2 and tube Ill extends axially of the tube a considerable distance as at 26; the flange being flattened by pressure exerted against the tube. It should be readily apparent that in a heat exchange apparatus with the fins shrunk or contracted upon the tubes in the foregoing manner efllcient transmission of heat between the tubes and fins will result. It will also be apparent that the flange i6 is stiflened and strengthened by the turning of the edge I 8 to provide a more rigid and durable fin In the modification of the invention shown in Figs. 4 and 5, a fln 28 has a slightly conical flange 30 defining an aperture 32 through which the tube 34 passes. Tools 36, 38 which may function in the manner of the tools 20, 22 reform the flange 30 upon the tube 34 giving it the final configuration shown in Fig. 5. As illustrated, the tool 36 is relieved as at 40 to effect the return bend 42. The reforming of the flange 30 in this manner results in a radial contraction of the aperture 32 defined by the flange upon the tube 34 with rigid frictional contact.

Obviously the shape and form of the tools and fin construction may be varied materially within the scope of our invention. Thus, without limitation as to form of the tools or fins, we consider the dominant feature of the present invention resides in the contraction or displacement of that area of the fln defining or adJaaosaasa cent the aperture upon the body of the heat exchange apparatus to provide adequate frictional contact between the parts; in the preferred form oi the invention the contracted area of the fin taking the form of an axially extending flange.

Having thus described our invention what we claim as new and desire to protect by Letters Patent is: v

1. A heat exchange apparatus comprising a supporting body and a fin engaging said body, said fin having a flanged portion extending axially oi the body in frictional engagement with said body, said portion having its outer end spaced from said fin and upturned, extending outwardly in a direction substantially parallel to said flu whereby the rigidity of the fin is enhanced.

2. A heat exchange apparatus comprising a tubular supporting body and a fin mounted upon said body, said fln having an aperture tor receiving said body defined by an axially extending flange, a portion of said flange extending radially from said body and spaced from said fin to stiffen the flange.

3. The method of making tubes for refrigeration coils and the like having fins comprising forming thin sheet metal fins eachwith an aperture defined by an integral annular flange, said apertures being oi a diameter to receive the tube, locating the fins in place upon the tube, and while supporting each of the flanges circumferentially upon opposite sides of their fins, reforming one circumferential portion of the respective flanges to cause a contraction of another circumferential portion of the same flange, said other portion being unreformed whereby the diameter of said apertures are reduced and the fins are secured to the tube.

4. The method 'of making tubes for refrigeration coils and the like having fins comprising forming thin sheet metal fins each with an aperture'defined by an integral annular flange, said apertures being of a diameter to receive the tube, locating the fins/in place upon the tube, and while supporting the flanges circumferentially upon opposite sides of their fins, turning the edges of said flanges to provide radially outward extending annular portions, whereby said flanges are contracted upon said tube and the fins and flanges are stiffened by said portions.

JOSEPH D. FORRER. LEWIS R. PROUGH. 

